Expansible bracelet having a coil spring mounted on link-like members



May 6, 1958 F. BURKLE EXPANSIBLE BRACELET HAVING A COIL SPRING MOUNTED 0N LINK-LIKE MEMBERS Filed May 28, 1956 agervnn:

@wmsmm United States Patent EXPANSIBLE BRACELET HAVING. A COIL SPRING MOUNTED ON LINK-LIKE MEM- BERS Fritz Biirkle, Schwann, near Pforzheim, Germany Application May 28, 1956, Serial No. 587,748 Claims priority, application Germany May 28, 1955 7 Claims. 01. 63

The present invention relates to an elastic bracelet and particularly to a bracelet for wrist-watches which conists of a spring, of a core composed of a number of individual. members and which is surrounded by the spring and is giving firmness to it, and of a casing enclosing the spring.

So-called articulated bracelets are i already known which consist of a number of members formed each as an individual spring and assembled by means of rivets, for instance three rivets for each member. It is, however, disadvantageous that these bracelets are more likely to be exposed to troubles due to their relatively complicated structure. They are also not very supple and rather expensive. The assembly of the known bracelets of the above mentioned type is relatively complicated, not at least due, to the manner in which the individual members are interconnected by means of rivets. Furthermore, it has already been proposed to connect the spring and the core with each other and to loosely lie the casing around these two parts. These. bracelets have the disadvantage that they are relatively complicated in construction and, consequently, expensive. Furthermore, a bracelet of this type will deform after a short time, since there is a relatively intense friction between the difierent parts and the individual members of the core which are connected with the spring thereby limiting its extension across the spring windings. Finally, there must be provided a relatively big space for the connecting means-the diiferent parts are connected with each other by n'vetsso that the individual members must be of a' relatively large and high form and the bracelet is, con-j sequently, not very supple.

It is, -therefore, the main object of this invention to provide a bracelet of the general characterdescribed which is simple in construction and inexpensive.

Another object of this invention is to provide a bracelet of the above said kind which does not deform after a certain time and between the individual parts of which there is only small friction.

Yet another object of this invention is to provide a bracelet of the before described type in which the different parts can be connected with each other in a simple manner without having recourse to rivets or the like and in which the individual members can be made more narrow and lower.

Still another object of this invention is to provide a bracelet which distinguishes by special suppleness.

With these and other objects in view, which will appear as the description proceeds, the invention consists of certain novel features of construction as will be particularly pointed out in the appended claims.

The manner of carrying the invention into effect is hereinafter described by way of example, reference being had to the accompanying drawings, in which: v

Fig. 1 is a front view of an individual member of the core,

Fig. 2 is a side view of the top part of an individual capsule-like link of the casing,

f are connected with each other.

of the capsule-like links are so constructed that the ice 2 Fig. 3 shows the part according to Fig. 2 as seen from the inside,

Fig. 4 is the side view of the bottom part of an indi-' vidual capsule-like link of the casing,

Fig. 5 shows the part according to Fig. 4 as seen from the inside,

Fig. 6 is a front view of the spring with the individual members of the core set in between its windings,

Fig. 7 is a sectional side view of a bracelet according to the invention,

Fig. 8 is a front view of an endpiece serving as locking member, and

Fig. 9 is a front view of a portion of the bracelet in expanded condition.

The bracelet consists of a continuous flat spiral spring 1, which is enclosed by a casing 2, and of a core 3. i The,

with shoulders 8 and 9 on which the corresponding part of'the spring is supported (see Fig. 6). In this way, the individual members of the core are in loose connection with two opposite end points of a turn of the spring andmove together with them.

The casing enclosing the spring consists of longish capsule-like links which connect the upper end 6 of each individual member 4 of the core 3 and the lower end 7, of the adjacent member with each other so as to limit the motion of the individual members when the bracelet is extended. Each capsule-like link consists of a top part 10 and a bottom part 11 which are connected with each other and enclose the corresponding parts of the spring 1 and of the core 3. Hereby, the bottom part 11 of the capsule-like link is smaller than the top part 10, such that the upper parts are lying against each other when the bracelet is contracted, whereas the bottom parts are somewhat spaced apart. The top parts 10 of the capsule-like links are provided on their ends with projecting flanges 12, 13 which are bent around the cor-' responding bottom parts 11 when the parts 10 and 11 individual members 4 of the core 3 can move between them, even after the two parts have been connected.

The top parts 10 are provided with lateral flaps 14, 15' against which the non-bent ends 6, 7 of the individual links 4 of the core 3 abut when the bracelet is extended." The bottom parts 11 of the capsule-like links have flanges 16, 17 bent inwardly which are to be set into the top parts 10 below the flanges 12 and 13 to be bent and between the flaps 14 and 15, when the capsule-like links are assembled.

With the exception of the spring there are used only parts manufactured by stamping, and these parts can be assembled in a simple manner. At first, the individual members are set in between two succeeding windings of the spring so that the corresponding parts of the spring are lying on the shoulders of the core member. Thereafter, the bottom parts of the capsule-like links are put on the individual members, whereby the upper end of each individual member is connected, respectively, with the lower end of the adjacent member. Finally, the top parts of the capsule-like links are fitted, and their projecting flanges are bent by means of a press. The capsule-like links permit that the spring with the core can move, since, otherwise, an extension of the bracelet would not be possible. They limit, however, the motion Patented May 6, 1958 The two parts 10, 11'

. 3- of the bracelet in order to prevent this latter to be overelongated, and the bracelet can be extended, therefore, only to a certain degree. By the fact that the bottom parts of the capsule-likedinks .are narrower than the top ones, jamming of the bracelet during its bending round is avoided and more suppleness is obtained. It is very easy to shorten the bracelet by bending high-the flanges of the topparts of the capsule-like links, removing one link, and taking out in lateral direction the corresponding individual member. Thereafter, the spring is correspondingly pinched off. In this manner there can be removed as many links as desired.

The endpieces 18 of the bracelet which form the locking member are flexibly connected with a plate 19 which is to be put against the outside of the two last links and which has at the upper and lower part flanges 20 and 21 which are bent around the band inwardly after the endpieces 18 have been fixed.

The new bracelet is above all suitable to be used with wrist-watches. However, it may also be used for other purposes, e. g. as adorning bracelet or the like.

The foregoing description is directed solely towards the constructions illustrated, but Idesire it to be understood that I reserve the privilege of resorting to all mechanical changes to which the device is susceptible, the invention being defined and limited only by the terms of the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. An elastic bracelet particularly for wrist watches comprising, in combination, a continuous substantially helical expansion spring; a series of individual elongated core members each having a body portion located inside said spring, said body portion .having shouldered ends remote from each other and respectively engaging said spring from the inside at opposite points of one turn thereof, so that during expansion of said spring the moving apart of said two end points of each turn thereof forces each of said members to carry out a turning movement about the point where one of said shouldered ends engages one, point of said spring, while the angle of turn for each member is determined by the increase of distance between said end points of the associated turn of said spring, said body portion having an extension projecting from each shouldered end thereof outwardly, one of said extensions being inserted between two turns of said spring, the other extension being inserted between the adjacent turn thereof; and easing means enclosing said spring and comprising a series of hollow links each associated with one turn of said spring and embracing at one end thereof one of said extensions of one of said members located at one side of said spring, and embracing at the opposite end thereof one of said extensions of an adjacent member located at the opposite side of said spring, so that when the bracelet is expanded said hollow links are forced to carry out a turning movement in a direction opposite to the turning movement of said core members due to the engagement between each of said links with two consecutive members at their respective opposite ends.

2. A bracelet as set forth in claim 1, wherein said body portion of said core members have the form of a straight fiat plate and said extensions are formed at an 1 angle to the length of said body portion, with said shoulders being located at diametrically opposed points of said body portion.

3. A bracelet as set forth in claim 1, wherein said hollow links each have lateral portions opposite to and spaced from said extensions of the associated core members when the bracelet is not expanded, so that said extensions abut against the respectively opposed lateral portion when by expansion of the bracelet said core members and said links carry out their respective turning movements whereby the expansion of said spring is positively limited.

4. A bracelet as set forth in claim 1, wherein each of said hollow links comprises a top and a bottom part which are connected together so as to enclose the corresponding parts of said spring and said core members.

5. A bracelet as set forth inclaim 1, wherein each of said hollow links comprises a top and a bottom part which are connected together so as to enclose the corresponding parts of said spring and said core members, and wherein .the bottom part of each of said hollow links is narrower than the :top part, the arrangement being such that when the bracelet is contracted said top parts are lying against each other while said bottom parts are spaced apart whereby bending of the bracelet in lengthwise direction is facilitated.

6. A bracelet as set forth in claim 1, wherein each of saidhollow links comprises a top and a bottom part which are connected together soas to enclose the corresponding parts of said spring and said core members, and wherein said top parts of said hollow links are provided on their ends with projecting flanges which are bent around the corresponding bottom parts when the topand bottom parts are connected together.

7. A bracelet as set forth in claim 1, wherein each of said hollow links comprises a top and a bottom part which are connected together so as to enclose the corresponding parts of said spring and said core members, and wherein said two parts of said hollow links are formed with lateral openings for permitting said core members .to carry out said turning movement relative to the associated links.

References Cited in the fileof this patent UNiTED STATES PATENTS 

